Time-setting device for electric timepiece

ABSTRACT

A time-setting mechanism in an electronic timepiece fitted with a seconds hand-locking device and a seconds-hand arbor, characterized in that the seconds-hand arbor is provided with a clutch and a locking cam, said clutch being adapted for on-off control of a seconds hand pinion relative to the arbor.

United States Patent 1 1 1- 3,731,481

Nakayama 1 May 8, 1973 [54] TIME-SETTING DEVICE FOR [56] References Cited ELECTRIC TIMEPIECE UNITED STATES PATENTS [75] Inventor: Yasuaki Nakayama,Tokyo.Japan I 1,982,495 11/1934 Brownmg ..58/85.5 X

2,594,106 4/1952 Weber ..58/85.5 Assigneez Citizen watch Company 2,607,188 Bourguin Tokyo Japan 3,233,400 2/1966 Haydon 1 ..58/34 v 3,443,375 5/1969 Cielaszyk ..58/85.5 [22] Filed: Mar. 24, 1972 3,548,587 12/1970 Wood ....58/85.5 X 3,587,224 6/1971 Gamer et a1..... ....58/85.5 X 1 [21] App 237,680 3,653,201 4 1972 Ogawa et a1 ..58/74 Primary Examiner-George H. Miller, Jr. [30] Foreign Application Priority Data Att0mey H0lman & Stem Mar. 27,1971 Japan ..46/218l9 [57] ABSTRACT 52 US. Cl ..ss/34, 58/85.5 A time setting mechanism in an electronic timepiece [51] Ilit. Cl. ..G04 9/00 fitted with a Seconds hand locking device and a [58] Field ofSearch ..58/3437, 74. 85.5 Seconds hand arbor Characterized in that the secondshand arbor is provided with a clutch and a locking cam, said c1utch being adapted for on-off control of a seconds hand pinion relative to the arbor.

4 Claims, 3 Drawing Figures Patnt'ed May s, 1973 3,731,481"

FIG!

TIME-SETTING DEVICE FOR ELECTRIC TIMEPIECE BACKGROUND OF THE INVENTION This invention relates to improvements in and relating to a time-setting mechanism in an electronic timepiece fitted with a seconds-hand locking device.

DESCRIPTION OF PRIOR ART In conventional electronic time pieces fitted with a time-setting mechanism it is a grave drawback that there is a back-feed of disadvantageous reactional force from the time-indicating hands through the gear train to the electronically operated prime mover in the movement.

It is a further drawback in conventional time-piece movements that the seconds hand cannot start instantly upon performing a time-setting job or a second-hand locking job, and on account of the unavoidable presence of backlashes in the time-keeping gear train of the watch or the like movement, especially when the seconds arbor cannot be fitted with somewhat larger size gear or gears owing to a highly complicated, compacted and crowded inside space of the movement.

SUMMARY OF THE INVENTION The object of the present invention is therefore to provide an improved time-setting mechanism for an electronic timepiece, especially a watch, which mechanism is capable of obviating the above-mentioned several drawbacks in conventional time-piece movements.

More specifically, the main object of the invention is to provide a highly improved time-setting mechanism of the above nature, capable of obviating the adverse reaction effect transmitted from the watch hand through the gear train back to the electronically operated prime mover of the timepiece movement, especially when the seconds-hand arbor is not fitted with larger gear or gears; the invention enables the seconds hand to start practically instantly upon performing a time-setting or seconds-hand locking job, in addition with the benefit that all the time display hands are kept in their mutual specifically set position upon performing the seconds-hand locking operation.

For this purpose, according to this invention, the seconds-hand arbor is provided with a clutch and a locking cam, said clutch being adapted for on-off control of a seconds-hand pinion relative to said arbor.

BRIEF DESCRIPTION OF THE DRAWING This and further objects, features and advantages will become more apparent from the following detailed description read in conjunction with the accompanying drawing, wherein,

FIG. 1 shows a schematic sectional view of a first embodiment.

FIG. 2 is a view similar to FIG. 1, but, illustrative of a second embodiment.

FIG. 3 is a perspective view of a clutch spring employed in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS Now, referring to the accompanying drawings, substantially two preferred embodiments of the invention will be described in detail.

In FIG. 1, numeral 1 denotes a seconds-hand arbor to which a clutch spring 2, and a control cam 3 are fixedly attached. A first second-hand pinion 4 is fixedly attached to the arbor as conventionally.

Numeral 5 represents a second seconds-hand pinion which is freely rotatably mounted on the arbor l and made somewhat larger than the first one, so as to accommodate a central bore for allowing its attachment to said arbor in the present embodiment. Numeral 6 represents a second third gear which is kept in meshing with a conventional fourth gear 8 and mounted freely rotatably on a conventional third gear arbor 7, said fourth gear 8 being operatingly connected through other gears (not shown) with a prime mover, (also not shown,) of the timepiece movement, for receiving driving torque therefrom in a known manner.

Numeral 9 represents a pressure spring which is attched at its root portion fixedly by means of a set screw 20 to a stationary member 21, (shown in part section) and exerts by its free end an upwardly directing urging axial pressure upon the pinion 5 which is thus positively prevented from axial fluctuations. During regular time-eeping operation, during occasional time-setting operations and during seconds-hand stopping operations as well.

Numeral 10 represents a set member mounting the second third gear 6 and made integral for unitary rotation therewith.

Further, numeral 11 represents an apertured jewel fixedly attached to the seat member 10, although in the drawing a gap is shown therebetween for purposes of clarity.

Numeral 12 represents a first third gear of the gear train which gear is fixedly attached to a conventional third pinion l3 and kept in gear meshing with said first seconds-hand pinion 4.

Numeral 14 represents a conventional second gear of the gear train which is kept in gear meshing with third pinion l3 and thus kept in cooperation with the gear train.

Numeral 15 represents a springy stop lever, the root end of which is attached fixedly by means of a set screw 22 to a second stationary plate member 23, only partially shown, of the timepiece movement, and formed with an inclined portion 16. When this stop lever 15 is forcibly flexed downwards in FIG. 1- by pressure engagement with a control lever 17 in case of a timesetting operation or of a seconds-hand locking operation, the tip or inward end of the lever 15 is brought into engagement with the clutch spring 2. The control lever 17 which is shown only in its cross-section for simplicity is adapted for movement from .its idle position shown to its working position at which the control lever is brought into pressure contact with the inclined portion 16 of the lever 15. Although not shown, the wearer of the timepiece or the watch may manipulate an outside operating member, preferably a conventional winding stem or the like, so as to shift the control lever 17 to-and-fro along the underside of said plate member 23 and between its idle and working position at will.

Although in the foregoing description, the clutch spring 2 has been shown and described as fixedly attached to the arbor 1, the invention is not limited to any suitable specific structure only. Thus, it suffices to employ such structure by which the second seconds-hand pinion can be separated in its operation from the arbor 1 when so desired, as will be described in greater detail hereinafter.

In FIG. 3, the clutch spring 2 is shown in its substantially enlarged perspective view. The clutch spring 2 when mounted in position as shown in FIG. 1 is so designed and arranged that when an axially directed pressure is applied on an upwardly and axially extending projection 2a as shown by an arrow a a second or peripheral projection 2b is flexed axially, but in the opposite direction as shown by the arrow b. A third axial projection 2a is provided so as to receive an axially urging force as applied to the projection 2a. By application of this axially urging force, the related peripheral projection 2b will be flexed axially as in the case of the similar peripheral projection 2b. As seen, the two axial projections 2a and 2a are arranged diametrally opposite with each other. A similar mutual relationship will be observed from FIG. 3 between the two peripheral projections 2b and 2b. A conventional escape wheel 19, shown only schematically, is made integral with the fourth gear 8, in a known manner.

The operation of the first embodiment shown in FIGS. 1 and is as follows:

When the timepiece movement is in its regular operating condition, motion is transmitted from an electronically operated prime mover, which may be a step motor, a drive balance wheel or the like which is electronically driven through a battery-charged electronic oscillator circuit and a mechanical vibrator, preferably of the quartz type, to the escape wheel 19, thence to fourth gear 8 for performing a unitary rotation therewith. Motion is further transmitted from fourth gear 8 through second third gear 6, second seconds-hand pinion 5, clutch spring 2, arbor 1, first second-hands pinion 4, first third gear 12 and third pinion 13 to second gear 14, thence to a minute hand 24 and hour hand 25.

When a time-setting or second-hands locking operation is performed, the outside manipulating member such as winding stem, not shown, is manipulated, so as to shift the control or locking lever 17 in the right-hand direction when seenin FIG. 1. Then the lever 17 is brought into pressurecontact with the inclined portion When a time-setting operation is carried out under these locked conditions, the minute hand 24 and the hour wheel can be set to a desired time point, since the turning effort caused by turning movement of the manipulating member such as the winding stem can be transmitted as usually to second gear 14, third pinion l3, first third gear 12 and first second pinion 4. But, under this locked condition where the seconds-hand arbor 1 has been locked through the locking cam 3 by the lever 17, the seconds hand shown at 26 in FIG. 1 and attached naturally fixed to the arbor 1, has been locked and thus is not adjusted in its position, there being only a relative slippage through a certain slip mechanism, not shown.

When the control or locking lever 17 is shifted from the aforementioned working position back towards its off-service or rest position by manipulating the winding stem in the reversed rotational direction, upon completion of the time-setting or the seconds-hand locking operation, the arbor l is released from its locked position into its rotatable position and the clutch spring 2 is coupled again with the pinion 5. Under these conditions, the force appearing during the time-setting or seconds-hand locking operation can not act upon the seconds pinion 5 so that the otherwise appearing backlash in the related gear train may be effectively suppressed; also, said gear train can instantly start, so far as the prime mover is acting regularly.

Next, referring to FIG. 2, the second embodiment of the invention will be described in detail. In this embodiment, same or similar parts as employed in the first embodiment will be enumerated with same reference nuarbor which is attached fixedly with clutch spring 102, i

L control or locking cam 103 and seconds pinion 104.

Numeral 130 represents a cup-shaped member' I which is loosely mounted on seconds-hand arbor 101, a

-16 of lever 15, thereby the latter beingforcibly flexed J downwards in FIG. 1, until the stop lever is brought into engagement with clutch spring 2, thereby the latter fixedly attached to the arbor 1 being disengaged from second seconds-hand pinion 5. Thus, the driving torque transmitted in the aforementioned way to the pinion 5, hence further motion transmission being interruptedthereat. Therefore, any reaction otherwise appearing during a time-setting or seconds-hand locking operation will not affect upon the regular function of the electronically operated prime mover.

By further manipulation of the manipulating member, so as to intentionally shift further rightwards in FIG. 1 until it engages with the control or locking earn 3 for locking the arbor l in position. With the locked condition of arbor l, first seconds-hand pinion 4, first third gear 12, third pinion 13, second gear 14 and the related gear train part are also locked simultaneously, thus the mutual and positional relationship among seconds hand, minute hand and hour hand being fixed in a position way.

second seconds-hand pinion being made integral with the upper part of said clutch member 130. A resilient ring member 131 which is made of rubber, soft plastics or similar resilient material, is fixedly mounted within the interior of said clutch member 130. The clutch member cooperates with clutch spring 102, so as to constitute jointly a clutch unit.

Numeral 119 is a seat member adapted for bringing the clutch spring into its disengaged position, when operated. The pressure spring 109 is a member similar to that shown at 9 in the first embodiment and serves for prevention of occasional fluctuation of position of the seconds-hand pinion 105 during the regular timekeeping operation of the timepiece movement and during a seconds-hand locking operation.

During the period of regular time-keeping operation of the timepiece movement, motion is transmitted through sixth gear 132, fifth gear 108 and intermediate gear 106 to second seconds-hand pinion 105. In this case, the pinion 105 and clutch member 130 are kept in unitary relationship with each other, and the torque will be transmitted through clutch spring 102 to the arbor 101, thence through pinion 104 and third gear 113 to second gear 114. During a time-setting or seconds-hand locking operation, the control or locking lever 117 which is similar to that shown at 17 in the foregoing embodiment will be shifted from the shown rest-position rightwards in FIG. 2 to its working position by manipulating the winding stem or similar manipulating member, so as to push stop or locking lever 118 upwards by striking upon the inclined portion 118a formed thereon. Thus, the locking lever 118 will urge the seat member 119 upwards which acts in turn upon clutch spring 102 to move upwards. In this way, the clutch unit is brought into disengaging position. Therefore, motion will be transmitted from the prime mover, not shown, through several gear train members to the clutch member 130; but, it is not transmitted to the seconds hand and its downstream members.

It will be seen from the foregoing that in this case no reaction force appearing in the time-setting or secondshand locking operation can be fed back to the prime mover.

By shifting the locking lever 117 further rightwards in FIG. 2 as was referred to hereinbefore in the case of the first embodiment, arbor 101 is locked through the locking cam 103 which is in turn acted upon by the tip end of said locking lever. In this way, third gear 113 is kept in gear meshing with the first seconds pinion 104; second gear 114 and the related gear train parts are kept in their locked position. Thus, the mutual relative position of seconds hand, minute hand and hour hand is kept in a certain positive relationship. When a timesetting job is brought about under these operational conditions, the turning effort exerted for causing the time-setting will be transmitted through second gear 114 and third gear 113 to the arbor 101. Since, in this case, the arbor 101 is kept in its locked position through the locking cam 103 by locking lever 117, the minute hand and the hour hand can be subjected to the time-setting operation, but it does not extend to the seconds hand now locked.

From the foregoing, it will be apparent that by use of the inventive mechanism so far shown and described, no adverse reactional force can be transmitted from the side of the seconds-hand arbor back to the prime mover during the time-setting or seconds-hand locking job; thus, even in this case, the delicate prime mover can operate to keep the time-keeping steps as usual. Even in the case of the seconds-hand adjustment upon locking thereof the relative position between the seconds hand, on the one hand, and the minute and I utilization of a certain outside signal source. There is no harmful backlash effect, even a delicate watch movement wherein a large gear cannot be provided to the seconds-hand arbor. Therefore, the invention is highly valuable as applied to precise and delicate electronically operated watch movements, particularly the quartz vibrator t pe.

It is naturally or the purpose of avoiding occasional mechanical clogging, that the third gear elements 6 and 12 are mounted slippable with each other, when a mechanical clogging torque should be applied thereto by virtue of their respective engagement with seconds gear elements 5 and 4.

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. A time-setting mechanism for an electronic timepiece, comprising in combination:

a rotatable seconds-hand arbor carrying a seconds hand; a first seconds-hand pinion element fixedly mounted on said arbor; a third gear disposed in gear meshing with said first pinion element and with a second gear;

a second seconds-hand pinion element looselymounted on said arbor and disposed in meshing with a gear train which is operable by a prime mover;

a clutch unit adapted for connecting said second pinion element into a unitary combination with said arbor; and

a locking cam fixedly mounted on said arbor and adapted to lock the arbor when subjected to a locking pressure.

' 2. A time-setting mechanism for an electronic timepiece using an electronically driven prime mover, comprising: a gear train including a seconds-hand arbor and a seconds-hand pinion mounted thereon, an associated gear for transmitting motion from said prime mover to said arbor, said mechanism being characterized in that said seconds-hand pinion is divided into two elements (4; 5) (104; 105), the first element (4) (104) being fixedly mounted on said arbor (1; 101), while the second element (5) (105) is loosely mounted on said arbor, said associated gear (13) (1 13) being disposed in meshing with said first pinion element and a second gear, said second pinion element being adapted for receiving motion from said associated gear, and both said pinion elements being engageable with each other through a clutch unit which is operable from outside.

3. The mechanism as set forth in claim 2, characterized by that said arbor (l)(l0l) carries fixedly a locking cam for locking the arbor when desired.

4. The mechanism asset forth in claim 2, characterized by that said associated gear is divided into two elements (6)(l2) which are mounted slippable with each other and kept in gear meshing with said second and first pinion elements (5)(4), respectively. 

1. A time-setting mechanism for an electronic timepiece, comprising in combination: a rotatable seconds-hand arbor carrying a seconds hand; a first seconds-hand pinion element fixedly mounted on said arbor; a third gear disposed in gear meshing with said first pinion element and with a second gear; a second seconds-hand pinion element loosely mounted on said arbor and disposed in meshing with a gear train which is operable by a prime mover; a clutch unit adapted for connecting said second pinion element into a unitary combination with said arbor; and a locking cam fixedly mounted on said arbor and adapted to lock the arbor when subjected to a locking pressure.
 2. A time-setting mechanism for an electronic timepiece using an electronically driven prime mover, comprising: a gear train including a seconds-hand arbor and a seconds-hand pinion mounted thereon, an associated gear for transmitting motion from said prime mover to said arbor, said mechanism being characterized in that said seconds-hand pinion is divided into two elements (4; 5) (104; 105), the first element (4) (104) being fixedly mounted on said arbor (1; 101), while the second element (5) (105) is loosely mounted on said arbor, said associated gear (13) (113) being disposed in meshing with said first pinion element and a second gear, said second pinion element being adapted for receiving motion from said associated gear, and both said pinion elements being engageable with each other through a clutch unit which is operable from outside.
 3. The mechanism as set forth in claim 2, characterized by that said arbor (1)(101) carries fixedly a locking cam for locking the arbor when desired.
 4. The mechanism as set forth in claim 2, characterized by that said associated gear is divided into two elements (6)(12) which are mounted slippable with each other and kept in gear meshing with said second and first pinion elements (5)(4), respectively. 